A liquid crystal compound means an organic compound having optical anisotropy and crystalline property in the molecular orientation. The liquid crystal compound is filled in a panel of a display device, and the like and rearranged by supply of voltage, whereby it may be used to control quantity of light penetrating through the panel. Also, the liquid crystal compound is polymerized in an aligned state and thereby may be used for an optical film, and the like such as a retardation film. In such a case, an alignment layer may be used in order to impart an order to the liquid crystal compound and in order for the liquid crystal compound to response regularly.
Generally, an alignment layer is formed by applying an aligning agent such as polyimide or polyvinyl alcohol on a substrate, and orientation is imparted by rubbing the alignment layer in a predetermined direction. Later, a polymerized liquid crystal compound is applied and aligned thereon to prepare a liquid crystal layer. However, since the rubbed alignment layer has insufficient adhesive strength to the liquid crystal layer, a problem in which the liquid crystal layer is peeled or contracted in a severe environment, such as a high-temperature or high-humidity environment, may occur. Further, a rubbing method may have problems in which static electricity or scratch is easily generated due to friction during a rubbing process, and fine dust can be generated problem from a rubbing fabric, and the like.
A non-contacting alignment method is known for solving the problems of rubbing method, and Patent document 1 discloses a light alignment method using light irradiation. However, such a method is cumbersome because a process for forming a special alignment layer should be performed.
[Patent document 1] KR Patent No. 10-2012-0008425